Unfortunately, I have to crate Muffin during the day while we're at work. She won't leave the others alone (and I'm afraid she be hurt or hurt someone else since she's a biter) and she is very destructive (surprising for a little dog).

The other three run free (in other words sleep on the bed/couch) during the day. Muffin had a little trouble with the crate at first, but lately she's fine. When she gets to where we can trust her, we'll leave her out all day like the others. All of ours went through being in the crate during the day.